Beginning Microsoft SQL Server 2008 ... - S3 Tech Training

Authentication
Chapter 2: Tools of the Trade
Watch out when using the Server selection dialog box. Although it’s usually pretty
reliable, there are ways of configuring a SQL Server so that it doesn’t broadcast. When
a server has been configured this way, it won’t show up in the list. Also, servers that
are only listening on the TCP/IP NetLib and don’t have a DNS entry will not show
up. You must, in this case, already know your IP address and refer to the server
using it.
You can choose between Windows Authentication and SQL Server Authentication. Windows Authentication
will always be available, even if you configured it as SQL Server Authentication. Logins using usernames
and passwords that are local to SQL Server (not part of a larger Windows network) are acceptable
to the system only if you specifically turn on SQL Server Authentication.
Windows Authentication
Windows Authentication is just as it sounds. You have Windows users and groups. Those Windows users
are mapped into SQL Server logins in their Windows user profile. When they attempt to log in to SQL
Server, they are validated through the Windows domain and mapped to roles according to the login.
These roles identify what the user is allowed to do.
The best part of this model is that you have only one password. (If you change it in the Windows domain,
then it’s changed for your SQL Server logins, too.) You don’t have to fill in anything to log in; it just takes
the login information from the way you’re currently logged in to the Windows network. Additionally, the
administrator has to administer users in only one place. The downside is that mapping this process can
get complex and, to administer the Windows user side of things, you must be a domain administrator.
SQL Server Authentication
The security does not care at all about what the user’s rights to the network are, but rather what you
explicitly set up in SQL Server. The authentication process doesn’t take into account the current network
login at all; instead, the user provides a SQL Server–specific login and password.
This can be nice because the administrator for a given SQL Server doesn’t need to be a domain administrator
(or even have a username on your network, for that matter) to give rights to users on the SQL Server.
The process also tends to be somewhat simpler than under Windows Authentication. Finally, it means
that one user can have multiple logins that give different rights to different things.
Try It Out Making the Connection
Let’s get logged in.
1. Choose the (local) option for the SQL Server.
2. Select SQL Server Authentication.
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